All aboard

The Japanese passenger train that is based on a roller-coaster is interesting. Since no motor is needed, it can be light and efficient, though it was noted that motorised vehicles can use regenerative braking and may be just as energy efficient (8 December, p 22).

However, it still operates as mass transport to many different destinations, so it must keep stopping, which wastes energy and time. There are ways of avoiding this, as exemplified by the Personal Rapid Transit system at Heathrow Airport in London. It uses small, automatic energy-efficient driverless vehicles to carry people non-stop from origin to destination.

It is strange that designers are still fixated on the traditional model of public transport, when automation can provide not only a higher level of personal service, but also greater energy efficiency.

To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.

To continue reading this article, log in or subscribe to New Scientist